The invention concerns an indicating instrument, in particular for a vehicle, having a pointer arranged on a rotatable pointer spindle of a measuring mechanism with a pointer hub and a pointer vane, the pointer vane having a region on the hub side that is covered or obscured from the viewer and a region remote from the hub that is visible for the viewer.
In contemporary indicating instruments there is often a first region of a pointer that is not visible for the viewer, because arranged in front of the pointer is a display which can indicate information independently of the pointer. Such embodiments require relatively long pointers and result in considerable pointer weights. This weight often becomes so great, on account of the counterweight on the side of the hub opposite from the pointer vane necessary for balancing masses, that the torque of contemporary measuring mechanisms is no longer adequate to move the pointer quickly enough or at all. If a smaller cross section is chosen for the pointer vane to make it more lightweight, vibrations of the kind that are unavoidable in a motor vehicle, for example, cause the pointer vane to oscillate, which makes it more difficult to read the indicating instrument and gives the impression of inadequate quality.
The invention is based on the problem of providing, an indicating instrument of the type stated at the beginning in such a way that its pointer has the lowest weight possible, without tending to oscillate as a result of vibrations of the indicating instrument. This problem is solved according to the invention by the covered region of the pointer vane on the pointer hub side having a profiled cross section.
In comparison with a pointer vane of a solid profile, such a profiled cross section allows the weight of the pointer to be reduced significantly while having the same strength. Since the profiled cross section according to the invention is covered or obscured, the profiling is not visible, so that the viewer is not confronted with a pointer of an unaccustomed appearance.
According to an advantageous development of the invention, the pointer has at least one light launching surface and can be illuminated by light which can be launched into it from a light source. As a result, the pointer can be additionally highlighted, in particular when the surroundings are dark, and the indicating instrument can be read better, without the driver of the vehicle being distracted from the traffic situation.
Light can be launched into the pointer from a single light source, arranged in the region of the pointer hub, independently of the position of the pointer, if, according to an advantageous development of the invention, the light launching surface is arranged in the region of the pointer hub and the region of the pointer vane on the pointer hub side has at least one bar extending continuously over its entire region in the longitudinal direction of the pointer.
An alternative embodiment is distinguished in that the light launching surface is arranged behind the region of the pointer vane on the pointer hub side, as seen from the pointer hub. In the case of such an embodiment, the profiling can be designed in any way desired, because there is no need to provide a possibility for light guidance through the profiled region. However, launching the light then requires a plurality of light sources arranged on a circular arc, an arcuate light source or an arcuate light strip. Since, however, this is to be arranged at a radial distance from the pointer hub and usually outside the measuring mechanism, such an arrangement does not result in space problems.
The profiled cross section of the pointer vane may be differently designed. It is of a very simple form and, if appropriate, allows flooding of the light from the launching surface on the pointer hub side through the entire pointer, if the region of the pointer vane on the pointer hub side is formed as an H, U, T or double-T profile.
The pointer vane can be produced in a particularly simple way and has very good light-guiding properties if, according to an advantageous development of the invention, the region of the pointer vane on the pointer hub side is formed as a U profile and the height of the crossbar is greater than the height of the lateral bars of the U.
The region of the pointer vane on the pointer hub side is advantageously provided with ribs, so that the pointer vane has in this region a latticework structure which, while being of particularly low weight, nevertheless ensures great rigidity of the pointer. The ribs are preferably arranged approximately vertically or approximately horizontally, the horizontal arrangement of the ribs offering particularly great rigidity of the pointer vane in the transverse direction, i.e. in the direction of the pointer deflection, and the vertical rib arrangement increasing the pointer stability in the direction perpendicular to the plane passed over by the pointer vane.
According to an advantageous development of the invention, the stability of the pointer is particularly great, with low pointer weight, if the ribs are arranged in an undulating or zigzag form. The undulating arrangement can further simplify the process for producing the pointer, which is generally an injection-molded component of plastic, whereas with the arrangement in zigzag form it is possible to achieve optimum weight and stability of the pointer.
The pointer is particularly stable and permits the mold to be easily opened or the pointer can be easily removed from the mold if the region of the pointer vane on the pointer hub side is formed as an H profile and the ribs extend above and/or below the middle bar of the H. The same applies if, according to an advantageous development of the invention, the region of the pointer vane on the pointer hub side is formed as a double-T profile and the ribs extend to the right and/or left side of the middle bar of the double T.
It contributes to a further increase in stability if, according to another development of the invention, the ribs on either side of the bar are offset in relation to one another. In the case of ribs in an undulating or zigzag form, they are preferably offset by half an interval in relation to one another on either side of the bar, further increasing stability.
If the covering is brought about by a display or part of an instrument panel, the pointer may initially extend between this display or the instrument panel and the measuring mechanism and extend with its end region in the plane of the display or instrument panel or above it if the pointer has behind the region of the pointer vane on the pointer hub side, as seen from the pointer hub, an offset directed toward the viewer and, following this offset, a pointer tip directed radially inward or outward. In this way, the display or part of the instrument panel that would otherwise be passed over by the pointer remains free for further indications.
Light can be launched optimally into such an offset pointer if the offset directed toward the viewer has toward the opposite side of the pointer a light launching projection which has the light launching surface at its end facing away from the viewer.
A particularly lightweight pointer with at the same time a very good light guiding capability is obtained if the pointer consists of polycarbonate.